package cn.edu.scau.cmi.mazhuanglong.esercise9;

public class EncryptAndDecrypt {
	String encrypt(String sourceString,String password) {
		char []p=password.toCharArray();
		int n=p.length;
		char[] c=sourceString.toCharArray();
		int m=c.length;
		for(int k=0;k<m;k++) {
			int mima=c[k]+p[k%n];
			c[k]=(char)mima;
		}
		return new String(c);
	}
	String decrypt(String sourceString, String password) {
		char[]p=password.toCharArray();
		int n=p.length;
		char[]c=sourceString.toCharArray();
		int m=c.length;
		for(int k=0;k<m;k++) {
			int mima=c[k]-p[k%n];
			c[k]=(char)mima;
		}
		return new String(c);
	}

}
